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How to make a self inflating balloon ?


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Trying to find how to put together one deflated 'party' balloon with a few grams of water in it and a chamber or packet with some compound also inside, that due to mechanical jerk they mix and produce a gas, perhaps CO2, so in less than a minute would inflate to something like 5 to 10 litres.

 

What household or simple compounds could achieve this ?

Would baking soda or baking powder or a more energetic something work ?

Ideas ?

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Baking soda is [ce] NaHCO3 [/ce] and that produces CO2 if mixed with (acidic) water. So that works... but you will have more than 1 drop of water in the balloon. (Don't go for strong acid: it eats your balloon, and possibly your hands too).

 

To get 10 liters of CO2, you need about 17 g CO2 (assuming T = 25 deg C). Therefore, you need about 33 g baking soda.

 

Then, assuming you have water of pH = 1 (that's pretty acidic), you need 4 liters of water. You can reduce that to 400 ml if you go for a solution of pH = 0, but then you'll need to be playing with strong acids, and I don't recommend it because of the poor balloon. You see that it's not so easy to make lots and lots of gas with a very limited amount of water.

 

I think "something more energetic" will destroy your balloon because the reaction will increase the temperature. (

 

And please don't try to go for air-bag material. It is toxic .

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I once saw a demonstration of balloons in liquid nitrogen. Very fun, they shrivel to almost no size when placed in liquid nitrogen. You can stuff a bunch of balloons into a small container, and when you pull them out, they reinflate.

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  • 4 weeks later...
  • 1 month later...

Hi.

Reviving this thread in case some other ideas come up, now with this approach:

 

Imagine a piece of pvc pipe, vertical, sealed at the bottom.

 

Pour some chemical compound in it.

Put some thin layer, membrane, or dividing separator on top of the compound.

Put an activator on top of the separator membrane.

 

Secure a deflated balloon on top of the pipe.

 

Tailored to ~24 hours, the activator should dissolve the separator and the two chemicals mix, producing gas that will inflate the balloon a few litres bringing an item to surface from the bottom of the sea.

 

Help with simple chemicals, please ?

 

Miguel

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Almost any kind of acid and a metal would theoretically work; as for the buoyancy power that would be a different story because, though hydrogen gas would be the lightest gas you could use, the products of a reaction like this would be the aqueous salt as well as the gas. Maybe a polyprotic acid would be more effective... depends on the materials you use.

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I guess the density of the gas isn't very important, since whatever is produced need only be less dense than sea water. Perhaps even a liquid product would work, although I guess you'd need a fairly speedy ascent and also the ability to carry a payload...

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Unless this is in very shallow water there's going to be a complication from the water pressure.

 

You fill the baloon with enough gas to get the contraption to rise. Then the gas expands and, if you didn't take account of this, it bursts the balloon. The contraption sinks again.

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I'd say use hydrochloric acid as the acid, granulated or powdered metal as the main reactant, and separate the two by a metal cylinder held in place by wax. The metal cylinder should be a metal that reacts slowly, and of the right length for the delay -- basically a fuse.

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  • 1 month later...

Take a can of 'canned air' (1,2-Difluoroethane iirc) and flip it up-side down. stick the nozzle in the balloon and fill with the compresed gas. Tie the balloon and it should inflate as the gas heats up (cooling the side of the balloon - or ziploc bag too, to freezing). Eventually it may pop.

 

That gas is not very good to get in you (although by far not the worst :P)

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